java.lang.Object
- org.eclipse.persistence.jpa.jpql.parser.AbstractExpression
- - org.eclipse.persistence.jpa.jpql.parser.HierarchicalQueryClause

All Implemented Interfaces:

Expression
```
public final class HierarchicalQueryClause
extends AbstractExpression
```
If a table contains hierarchical data, then rows can be selected in a hierarchical order using the hierarchical query clause.
START WITH specifies the root row(s) of the hierarchy.
CONNECT BY specifies the relationship between parent rows and child rows of the hierarchy.
BNF: hierarchical_query_clause ::= [start_with_clause] connectby_clause [order_siblings_by_clause]

Since:

2.5

Version:

2.5

Author:

Pascal Filion

See Also:

StartWithClause, ConnectByClause, OrderSiblingsByClause

Field Summary
- Fields inherited from class org.eclipse.persistence.jpa.jpql.parser.AbstractExpression
  COMMA, DOT, DOUBLE_QUOTE, LEFT_CURLY_BRACKET, LEFT_PARENTHESIS, NOT_DEFINED, RIGHT_CURLY_BRACKET, RIGHT_PARENTHESIS, SINGLE_QUOTE, SPACE, UNDERSCORE
- Fields inherited from interface org.eclipse.persistence.jpa.jpql.parser.Expression
  ABS, ALL, AND, ANY, AS, AS_OF, ASC, AVG, BETWEEN, BIT_LENGTH, BOTH, CASE, CAST, CHAR_LENGTH, CHARACTER_LENGTH, CLASS, COALESCE, COLUMN, CONCAT, CONNECT_BY, COUNT, CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP, DELETE, DELETE_FROM, DESC, DIFFERENT, DISTINCT, DIVISION, ELSE, EMPTY, END, ENTRY, EQUAL, ESCAPE, EXCEPT, EXISTS, EXTRACT, FALSE, FETCH, FIRST, FROM, FUNC, FUNCTION, GREATER_THAN, GREATER_THAN_OR_EQUAL, GROUP_BY, HAVING, IN, INDEX, INNER, INNER_JOIN, INNER_JOIN_FETCH, INTERSECT, IS, IS_EMPTY, IS_NOT_EMPTY, IS_NOT_NULL, IS_NULL, JOIN, JOIN_FETCH, KEY, LAST, LEADING, LEFT, LEFT_JOIN, LEFT_JOIN_FETCH, LEFT_OUTER_JOIN, LEFT_OUTER_JOIN_FETCH, LENGTH, LIKE, LOCATE, LOWER, LOWER_THAN, LOWER_THAN_OR_EQUAL, MAX, MEMBER, MEMBER_OF, MIN, MINUS, MOD, MULTIPLICATION, NAMED_PARAMETER, NEW, NOT, NOT_BETWEEN, NOT_EQUAL, NOT_EXISTS, NOT_IN, NOT_LIKE, NOT_MEMBER, NOT_MEMBER_OF, NULL, NULLIF, NULLS, NULLS_FIRST, NULLS_LAST, OBJECT, OF, ON, OPERATOR, OR, ORDER_BY, ORDER_SIBLINGS_BY, OUTER, PLUS, POSITION, POSITIONAL_PARAMETER, QUOTE, REGEXP, SCN, SELECT, SET, SIZE, SOME, SQL, SQRT, START_WITH, SUBSTRING, SUM, TABLE, THEN, TIMESTAMP, TRAILING, TREAT, TRIM, TRUE, TYPE, UNION, UNKNOWN, UPDATE, UPPER, VALUE, WHEN, WHERE

Constructor Summary

Constructors
Constructor Description

HierarchicalQueryClause(AbstractExpression parent)
Creates a new HierarchicalQueryClause.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`accept(ExpressionVisitor visitor)`	Visits this `Expression` by the given `visitor`.
`void`	`acceptChildren(ExpressionVisitor visitor)`	Visits the children of this `Expression`.
`JPQLQueryBNF`	`findQueryBNF(Expression expression)`	Retrieves the `JPQLQueryBNF` that represents the fragment of this `Expression` that was used when parsing the given `Expression`.
`Expression`	`getConnectByClause()`	Returns the `Expression` representing the CONNECT BY clause.
`Expression`	`getOrderSiblingsByClause()`	Returns the `Expression` representing the ORDER SIBLINGS BY clause.
`JPQLQueryBNF`	`getQueryBNF()`	Returns the BNF of this `Expression`.
`Expression`	`getStartWithClause()`	Returns the `Expression` representing the START WITH clause.
`boolean`	`hasConnectByClause()`	Determines whether the CONNECT BY clause is defined.
`boolean`	`hasOrderSiblingsByClause()`	Determines whether the ORDER SIBLINGS BY clause is defined.
`boolean`	`hasSpaceAfterConnectByClause()`	Determines whether a whitespace was found after the `CONNECT BY` clause.
`boolean`	`hasSpaceAfterStartWithClause()`	Determines whether a whitespace was found after the `START WITH` clause.
`boolean`	`hasStartWithClause()`	Determines whether the START WITH clause is defined.

Methods inherited from class org.eclipse.persistence.jpa.jpql.parser.AbstractExpression
children, getGrammar, getIdentifierVersion, getLength, getOffset, getParent, getQueryBNF, getRoot, isAncestor, orderedChildren, populatePosition, toActualText, toParsedText, toString

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - HierarchicalQueryClause
```
public HierarchicalQueryClause(AbstractExpression parent)
```
    Creates a new HierarchicalQueryClause.
    
    Parameters:
    
    parent - The parent of this expression
- Method Detail
  - accept
```
public void accept(ExpressionVisitor visitor)
```
    Visits this Expression by the given visitor.
    
    Parameters:
    
    visitor - The ExpressionVisitor to visit this object
  - acceptChildren
```
public void acceptChildren(ExpressionVisitor visitor)
```
    Visits the children of this Expression. This method can be used to optimize traversing the children since a new list is not created every time Expression.children() is called.
    This does not traverse the Expression sub-hierarchy, use a subclass of AbstractTraverseChildrenVisitor in order to traverse the entire sub-hierarchy.
    
    Parameters:
    
    visitor - The visitor to visit the children of this object.
  - findQueryBNF
```
public JPQLQueryBNF findQueryBNF(Expression expression)
```
    Retrieves the JPQLQueryBNF that represents the fragment of this Expression that was used when parsing the given Expression.
    
    Specified by:
    
    findQueryBNF in interface Expression
    
    Overrides:
    
    findQueryBNF in class AbstractExpression
    
    Parameters:
    
    expression - The Expression that is a descendant of this one
    
    Returns:
    
    The JPQLQueryBNF that was used to parse the given expression
  - getConnectByClause
```
public Expression getConnectByClause()
```
    Returns the Expression representing the CONNECT BY clause.
    
    Returns:
    
    The expression representing the CONNECT BY clause
  - getOrderSiblingsByClause
```
public Expression getOrderSiblingsByClause()
```
    Returns the Expression representing the ORDER SIBLINGS BY clause.
    
    Returns:
    
    The expression representing the ORDER SIBLINGS BY clause
  - getQueryBNF
```
public JPQLQueryBNF getQueryBNF()
```
    Returns the BNF of this Expression.
    
    Returns:
    
    The JPQLQueryBNF, which represents the grammar of this Expression
  - getStartWithClause
```
public Expression getStartWithClause()
```
    Returns the Expression representing the START WITH clause.
    
    Returns:
    
    The expression representing the START WITH clause
  - hasConnectByClause
```
public boolean hasConnectByClause()
```
    Determines whether the CONNECT BY clause is defined.
    
    Returns:
    
    true if the query that got parsed had the CONNECT BY clause
  - hasOrderSiblingsByClause
```
public boolean hasOrderSiblingsByClause()
```
    Determines whether the ORDER SIBLINGS BY clause is defined.
    
    Returns:
    
    true if the query that got parsed had the ORDER SIBLINGS BY clause
  - hasSpaceAfterConnectByClause
```
public boolean hasSpaceAfterConnectByClause()
```
    Determines whether a whitespace was found after the CONNECT BY clause. In some cases, the space is owned by a child of the hierarchical query clause.
    
    Returns:
    
    true if there was a whitespace after the CONNECT BY clause and owned by this expression; false otherwise
  - hasSpaceAfterStartWithClause
```
public boolean hasSpaceAfterStartWithClause()
```
    Determines whether a whitespace was found after the START WITH clause. In some cases, the space is owned by a child of the hierarchical query clause.
    
    Returns:
    
    true if there was a whitespace after the START WITH clause and owned by this expression; false otherwise
  - hasStartWithClause
```
public boolean hasStartWithClause()
```
    Determines whether the START WITH clause is defined.
    
    Returns:
    
    true if the query that got parsed had the START WITH clause

Class HierarchicalQueryClause

Field Summary

Fields inherited from class org.eclipse.persistence.jpa.jpql.parser.AbstractExpression

Fields inherited from interface org.eclipse.persistence.jpa.jpql.parser.Expression

Constructor Summary

Method Summary

Methods inherited from class org.eclipse.persistence.jpa.jpql.parser.AbstractExpression

Methods inherited from class java.lang.Object

Constructor Detail

HierarchicalQueryClause

Method Detail

accept

acceptChildren

findQueryBNF

getConnectByClause

getOrderSiblingsByClause

getQueryBNF

getStartWithClause

hasConnectByClause

hasOrderSiblingsByClause

hasSpaceAfterConnectByClause

hasSpaceAfterStartWithClause

hasStartWithClause